1. Field of the Invention
The present invention relates to electromagnetic radiation in the visible spectrum (including ultra-violet and infrared) modulator arrays. The present invention is further in the field of semiconductor structures. The present invention further relates to the field of integrated devices and circuits. The present invention further relates to the field of electronic displays. The present application describes semiconductor structures whose optical characteristics can be actively modified so that they can modulate light. The implementation is not limited to a specific technology, and applies to either the invention as an individual component or to inclusion of the present invention within larger systems.
2. Brief Description of Related Art
In nature colors are not emitted by active elements, like it occurs for electronic displays, but they are the result of reflection of incident light. Some animals, such as butterflies, achieve a broad range of color, brightness and contrast by processing interferometrically incident light. In an interferometric structure incident light is reflected in a way that specific wavelengths interfere with each other. If two waves of same frequency have the same phase the interference is constructive and the result is a very vivid color. Constructive interference of light can be obtained by determining selectively the optical paths of the optical waves.
Interferometric devices that reflect incident light to produce electronic displays that use only ambient light already exist. They are based on MEMS (Micro Electro Mechanical Systems) technologies that change the length of the optical paths by applying an electrostatic voltage to the MEMS structure. However MEMS have moving elements, therefore are subject to poor reliability because the elements degrade with time and eventually fail. Moreover MEMS are certainly faster than LCD (liquid Crystal Displays) but are still slow for very fast applications. Furthermore MEMS are typically by-stable and assume only two states, therefore are more prone to digital control.
It is desirable to have reflective displays that utilizes the interferometric concept of incident light with structures that are faster, more reliable, and more cost effective than the MEMS technologies and possibly that can be controlled in analog fashion.